BACKGROUND: Currently 30 chest compressions and 2 ventilations with an inspiratory time of 1 s are recommended during cardiopulmonary resuscitation with an unprotected airway, thus spending about 15% instead of 40% of resuscitation time on ventilation. Time could be gained for chest compressions when reducing inspiratory time from 2 s to 1 s, however, stomach inflation may increase as well. METHODS: In an established bench model we evaluated the effect of reducing inspiratory time from 2 s to 1 s at different lower oesophageal sphincter pressure (LOSP) levels using a novel peak inspiratory-flow and peak airway-pressure-limiting bag-valve-mask device (Smart-Bag). RESULTS: A reduction of inspiratory time from 2 s to 1 s resulted in significantly lower peak airway pressure with LOSP of 0.49 kPa (5 cm H2O), 0.98 kPa (10 cm H2O) and 1.47 kPa (15 cm H2O) and an increase with 1.96 kPa (20 cm H2O). Lung tidal volume was reduced with 1 s compared to 2 s. When reducing inspiratory time from 2 s to 1 s, stomach inflation occurred only at a LOSP of 0.49 kPa (5 cm H2O). CONCLUSIONS: In this model of a simulated unprotected airway, a reduction of inspiratory time from 2 s to 1 s using the Smart-Bag resulted in comparable inspiratory peak airway pressure and lower, but clinically comparable, lung tidal volume. Stomach inflation occurred only at a LOSP of 0.49 kPa (5 cm H2O), and was higher with an inspiratory time of 2 s vs 1 s.
BACKGROUND: Currently 30 chest compressions and 2 ventilations with an inspiratory time of 1 s are recommended during cardiopulmonary resuscitation with an unprotected airway, thus spending about 15% instead of 40% of resuscitation time on ventilation. Time could be gained for chest compressions when reducing inspiratory time from 2 s to 1 s, however, stomach inflation may increase as well. METHODS: In an established bench model we evaluated the effect of reducing inspiratory time from 2 s to 1 s at different lower oesophageal sphincter pressure (LOSP) levels using a novel peak inspiratory-flow and peak airway-pressure-limiting bag-valve-mask device (Smart-Bag). RESULTS: A reduction of inspiratory time from 2 s to 1 s resulted in significantly lower peak airway pressure with LOSP of 0.49 kPa (5 cm H2O), 0.98 kPa (10 cm H2O) and 1.47 kPa (15 cm H2O) and an increase with 1.96 kPa (20 cm H2O). Lung tidal volume was reduced with 1 s compared to 2 s. When reducing inspiratory time from 2 s to 1 s, stomach inflation occurred only at a LOSP of 0.49 kPa (5 cm H2O). CONCLUSIONS: In this model of a simulated unprotected airway, a reduction of inspiratory time from 2 s to 1 s using the Smart-Bag resulted in comparable inspiratory peak airway pressure and lower, but clinically comparable, lung tidal volume. Stomach inflation occurred only at a LOSP of 0.49 kPa (5 cm H2O), and was higher with an inspiratory time of 2 s vs 1 s.
Authors: Achim von Goedecke; Horst G Wagner-Berger; Karl H Stadlbauer; Anette C Krismer; Juliusz Jakubaszko; Christian Bratschke; Volker Wenzel; Christian Keller Journal: Resuscitation Date: 2004-11 Impact factor: 5.262
Authors: Arthur B Sanders; Karl B Kern; Robert A Berg; Ronald W Hilwig; Joseph Heidenrich; Gordon A Ewy Journal: Ann Emerg Med Date: 2002-12 Impact factor: 5.721